MySQL 8.0 Release Notes
MySQL Enterprise Audit previously used tables in the mysql
system database for persistent storage of filter and user
account data. For enhanced flexibility, the new
audit_log_database
server
system variable now permits specifying other databases in the
global schema namespace at server startup. The
mysql
system database is the default setting
for table storage.
(WL #15500)
Microsoft Windows: Added MSVC Code Analysis support for Visual Studio 2017 and higher. This adds a new MSVC_CPPCHECK (defaults to OFF) CMake option that either enables or disables this analysis on the current directory and its subdirectories. (Bug #34828882)
Downgraded curl deprecation warnings to -Wno-error for curl versions greater than 7.86 when MySQL is built with a GNU compiler or clang. (Bug #35111625)
On macOS, added -framework CoreFoundation and -framework SystemConfiguration when linking the curl interface to link with shared system libraries as needed. (Bug #35104962)
Replaced the MY_INCLUDE_SYSTEM_DIRECTORIES
macro with library interfaces.
(Bug #35018072, Bug #35028089, Bug #35072295)
Improved CMake code to support alternative linkers. (Bug #34963568)
Removed the deprecated Docs/mysql.info
file
from the build system.
(Bug #34960126)
Added a top-level .clang-tidy
file and
associated .clang.tidy
files in the
strings/
and mysys/
directories. Also enabled compdb support to
enable clang-tidy usage on header files.
(Bug #34917075)
Removed several unmaintained or unused C++ source files for functionality such as uca-dump and uctypedump. (Bug #34898978)
Added a CMake build option to enable colorized compiler output
for GCC and Clang when compiling on the command line. To enable,
pass -DFORCE_COLORED_OUTPUT=1
to
CMake.
(Bug #34897192)
On Windows, also install .pdb files for associated .dll files if they are found for 3rd-party libraries. (Bug #34863555)
Enterprise Linux 8 and Enterprise Linux 9 builds now use GCC 12 instead of GCC 11. (Bug #34829151)
Building with -static-libgcc -static-libstdc++ now also builds the bundled protobuf with static libraries, as required.
Thanks to Alex Xing for the contribution. (Bug #110216, Bug #35123848)
INSTALL COMPONENT
now includes
the SET
clause, which sets the values of
component system variables while installing one or more
components. The new clause reduces the inconvenience and
limitations associated with the other ways of assigning variable
values. For usage information, see
INSTALL COMPONENT Statement.
(WL #10916)
User-defined collations (see Adding a Collation to a Character Set) are now deprecated. Either of the following now causes a warning to be written to the log:
Any occurrence of COLLATE
followed by the
name of a user-defined collation in an SQL statement
Use of the name of a user-defined collation as the value of
collation_server
,
collation_database
, or
collation_connection
You should expect support for user-defined collations to be removed in a future version of MySQL. (WL #14277)
MySQL Enterprise Edition now provides data masking and de-identification capabilities based on components, rather than being based on a plugin library that was introduced in MySQL 8.0.13. The component implementation provides dedicated privileges to manage dictionaries and extends the list of specific types to include:
Canada Social Insurance Number
United Kingdom National Insurance Number
International Bank Account Number
Universally Unique Identifier (UUID)
An improved table-based dictionary registry replaces the file-based dictionary used by the plugin. For a summary of the differences between the component and plugin implementations, see Data-Masking Components Versus the Data-Masking Plugin. Existing plugin users should uninstall the server-side plugin and drop its loadable functions before installing the new MySQL Enterprise Data Masking and De-Identification components. (Bug #33851601, WL #12641)
The Performance Schema Server Telemetry Traces service is added in this release. An interface which provides plugins and components a way to retrieve notifications related to SQL statements' lifetime.
For more information on this interface, see the Server telemetry traces service section in the MySQL Source Code documentation.
The following were added:
Status variable
Telemetry_traces_supported
.
Whether server telemetry traces is supported. (Boolean)
TELEMETRY_ACTIVE
column was added to the
threads
table. Indicates
whether the thread has an active telemetry session attached.
(WL #15059)
The length of a digest for the query rewrite plugin should be 32 bytes, but this was not always enforced. (Bug #34991760)
Important Change: For platforms on which OpenSSL libraries are bundled, the linked OpenSSL library for MySQL Server has been updated to version 1.1.1t. Issues fixed in OpenSSL version 1.1.1t are described at https://www.openssl.org/news/cl111.txt. (Bug #35092429)
Replication:
As part of ongoing work to change old terminology used in MySQL
products, the terms “master”, “slave”,
and “MTS” have been replaced in error messages
relating to MySQL Replication by “source”,
“replica”, and “MTA”, respectively.
This includes all error messages listed in
messages_to_clients.txt
and
messages_to_error_log.txt
relating to
replication; the present task does not perform this replacement
for messages used in other contexts.
See the MySQL 8.0 Error Message Reference, for more information. (Bug #108422, Bug #34594819, WL #14191)
Replication:
mysqlbinlog
--start-position
now accepts
values up to 18446744073709551615, unless the
--read-from-remote-server
or
--read-from-remote-source
option is also used, in which case the maximum is 4294967295.
(Bug #77818, Bug #21498994)
Binary packages that include curl rather than linking to the system curl library have been upgraded to use curl 7.88.1. (Bug #34828111)
The use of a generated column with
DEFAULT(
to specify the default value for a named column is not permitted
and now emits an error message.
(Bug #34463652, Bug #34369580)col_name
)
The new TELEMETRY_LOG_ADMIN
privilege now enables telemetry log configuration. This
privilege is defined by the telemetry_log
plugin, which is deployed exclusively through MySQL HeatWave on AWS.
(Bug #111395, Bug #35494180)
It is now possible to return the Statement ID to the client for
successfully executed statements. To enable this per session,
add statement_id
to the value of
session_track_system_variables
,
or set
session_track_system_variables
to the special value *
(asterisk).
(WL #15418)
NDB Cluster:
Occasional temporary errors which could occur when opening a
table from the NDB
dictionary while
repeatedly performing concurrent schema operations were not
retried.
(Bug #34843889)
NDB Cluster:
During iteration, ordered index scans retain a cursor position
within each concurrently scanned ordered index fragment. Ordered
index fragments are modified and balanced as a result of
committing DML transactions, which can require scan cursors to
be moved within the tree. When running with query threads
configured
(AutomaticThreadConfig
set to 1), multiple threads can access the same index fragment
tree structure, and the scans of multiple threads can have their
cursors present in the same structure.
The current issue arose due to an assumption in the logic for moving scan cursors when committing DML operations that all scan cursors belonged to the LDM thread owning the index fragment, which did not allow for the possibility that such fragments might belong to query threads. (Bug #33379702)
References: See also: Bug #32257063.
InnoDB:
Error messages related to
innodb_doublewrite
now appear
in the error log.
(Bug #34883045, Bug #109330)
InnoDB: Prevent online DDL operations from accessing out-of-bounds memory. (Bug #34750489, Bug #108925)
InnoDB:
ALTER TABLE ...
AUTO_INCREMENT
could be set to less than MAX + 1 and
not forced to MAX + 1.
(Bug #33419246, Bug #105092)
InnoDB:
Innodb_data_pending_fsyncs
could show extremely high inaccurate values because of a
variable overflow.
(Bug #30133150)
Partitioning:
Some IN()
queries on partitioned tables were
not always handled correctly.
(Bug #34801284)
References: This issue is a regression of: Bug #32311183.
Partitioning:
Queries using the INDEX_MERGE
optimizer hint was not handled correctly in all cases.
(Bug #34797257)
Replication: XA transactions whose XIDs contained null bytes could not be recovered. (Bug #34918985)
Replication:
When binlog_order_commits
was
set equal to 1
, for any two transactions and
for any sub-step of the commit phase, the transaction that was
written to the binary log first did not always execute the
sub-step first, as expected.
(Bug #34703698)
Replication: Some binary log events were not always handled correctly. (Bug #34617506)
Replication: The binary log recovery process did not report all possible error states. (Bug #33658850)
Replication:
Following
CHANGE
REPLICATION SOURCE TO
SOURCE_CONNECTION_AUTO_FAILOVER=1
, failover generated
a number of misleading warnings in the log that implied there
were problems when in fact conditions were those expected for
such a failover. These log messages have been updated
accordingly.
(Bug #32135376)
Replication: When a transaction failed, as a side effect, extraneous error messages relating the replication data repositories were written to the log. Now in such cases, we suppress such error messages, which are not directly related to the issue of the failed transaction or its cause. (Bug #19820134)
Replication:
Setting binlog_order_commits
to
OFF
could lead to a missed GTID in the next
binary log file's Previous_gtids
event.
Our thanks to Yewei Xu and the Tencent team for the contribution. (Bug #109485, Bug #34930969)
Replication:
Corrected the SQL statements suggested in the error message text
for
ER_RPL_REPLICA_ERROR_RUNNING_QUERY
.
Our thanks to Dan McCombs for the contribution. (Bug #109154, Bug #34822612)
Replication: A hash scan builds a hash of changes, scans the target table or index, and applies any matching change for the current entry. In the build phase, it uses only the before image, and skips any after image. Problems arose in some cases because generated columns were computed for the (skipped) after image, leading to replication errors. This is fixed by not computing generated columns any longer for seek-only calls such as hash scans.
Our thanks to dc huang for the contribution. (Bug #107366, Bug #34198907)
Replication:
In certain rare cases, it was possible to set
gtid_mode=OFF
for one session
while another session, after
WAIT_FOR_EXECUTED_GTID_SET()
was
issued by a user in this second session, was still waiting for
the next GTID set from the first session. This could result in
the second session waiting indefinitely for the function to
return.
(Bug #99921, Bug #31505993)
Group Replication:
Accessing the Performance Schema
replication_group_communication_information
and replication_group_member_stats
tables in parallel sometimes caused subsequent group replication
operations to hang.
(Bug #34870181)
Group Replication: In certain cases, the group replication secondary node unexpectedly shut down while purging the relay log. (Bug #34397106)
Group Replication:
When shutting down the Group Replication plugin, the order in
which the associated events were reported the error log
sometimes led to confusion. To remove any doubts, we now make
sure that Plugin group_replication reported: 'Plugin
'group_replication' has been stopped.
is in fact the
last log message relating to the shutdown, written only when all
other events associated with shutting down the plugin have been
logged.
(Bug #109345, Bug #34887491)
Microsoft Windows:
The authentication_fido_client
plugin stopped
responding during the authentication process if it was unable to
find a FIDO device on the Windows client host.
(Bug #34918044)
In certain cases,
CONVERT(
was rejected with the error
Cannot convert string '\x--...' from binary to
utf16.
(Bug #35129361)utf8mb3_column
USING UTF16)
When joining two tables on a string column, and the column from one of the tables has an additional predicate comparing it with a temporal literal, constant propagation in some cases incorrectly caused the join condition to be modified such that it used temporal rather than string semantics when comparing the strings. This caused incorrect results to be returned from the join. (Bug #35115909)
Error messages returned after calling the
mysql_reset_connection()
C API
function in a prepared statement did not identify the function
name properly.
(Bug #35107280)
Fixed a regression in a previous fix for an issue with windowing functions.
Our thanks to Dmitry Lenev for the contribution. (Bug #35061924)
References: This issue is a regression of: Bug #34572136.
When replacing subqueries in transforms, the internal flag
showing whether a given query block contains any subqueries
(PROP_SUBQUERY
) was not updated afterwards.
(Bug #35060385)
A client setting the character set to an impermissible client
character set (ucs2
,
utf16
, utf16le
, or
utf32
) could cause unexpected behavior when
the client used an authentication plugin.
(Bug #35054579)
EXPLAIN ANALYZE
displayed 0 when
the average number of rows was less than 1. To fix this, we now
format numbers in the output of EXPLAIN
ANALYZE
and EXPLAIN FORMAT=TREE
such that numbers in the range 0.001-999999.5 are printed as
decimal numbers, and numbers outside this range are printed
using engineering notation (for example:
1.23e+9
, 934e-6
). In
addition, trailing zeroes are no longer printed, and numbers
less than 1e-12
are printed as
0
.
This helps ensure consistent precision regardless of the number's value and improve readability, while producing minimal rounding errors. (Bug #34990948)
The NTILE()
function did not work
correctly in all cases.
(Bug #34986665)
Some joins on views did not perform correctly. (Bug #34985359)
Transforming a correlated scalar subquery to a derived table led
to a wrong result for InnoDB
tables
when the subquery included duplicate predicates. An example of a
query which could be affected by this issue is shown here:
SELECT * FROM t1
WHERE (
SELECT t2.a FROM t2
WHERE t2.a = t1.a AND t2.a = t1.a
) > 0;
(Bug #34973220)
Fixed an assert in sql/item_strfunc.cc
that
could potentially lead to issues with the
SPACE()
function.
(Bug #34962821)
Using ROW_COUNT()
as the
length
argument to
LPAD()
or
RPAD()
did not perform as
expected.
(Bug #34961236)
A query with a window function having an expression with a
CASE
function in its ORDER
BY
clause could lead to a server exit.
(Bug #34933045)
The fix for a previous issue introduced an assertion in debug
builds when optimizing a HAVING
clause.
(Bug #34923792)
References: This issue is a regression of: Bug #33725415.
When using mysqld_multi
, the system that
obscures "--password" usage as "--password=*****" would also
match "--password-history" and "--password-require-current"
definitions as "--password", but now explicitly checks for
"--password=" instead.
(Bug #34918740)
In some cases, calling the
mysql_bind_param()
C API
function could cause the server to become unresponsive.
(Bug #34869076)
The authentication_oci_client
plugin was
unable to open a valid configuration file if any of its entries
contained an equals sign character separated by spaces (for
example, key_file =
/home/user/.oci/oci_api_key.pem
). Now, both
'key
=value
'
and 'key
=
value
' entry formats are supported.
(Bug #34864078)
Incorrect results were returned when the result of an
INTERSECT
or
EXCEPT
operation was joined with
another table. This issue affected these operations in such
cases when used with either DISTINCT
or
ALL
.
(Bug #34843764)
When preparing a view query, the operation used the system character set (instead of the character set stored in data dictionary) and then reported an invalid character-string error. (Bug #34800905)
Prepared statements that operate on derived tables, including views, could stop unexpectedly due to problems with the code for reopening tables after an error. (Bug #34798403)
Removed an assertion raised in certain cases by the
RANDOM_BYTES()
function in debug
builds.
(Bug #34781507)
There was an issue in how persisted variables were set on startup, causing certain variables not to get properly set to their persisted value. (Bug #34751419)
The MAKETIME()
function did not
perform correctly in all cases.
(Bug #34745241)
Some functions with multiple arguments did not produce the expected results. (Bug #34741801)
A table reference in an ORDER BY
outside the
parenthesized query block in which the table was used, and which
query block had no LIMIT
or ORDER
BY
of its own, raised an error.
(Bug #34704011)
References: This issue is a regression of: Bug #103954, Bug #32980249.
A left join with an impossible condition as part of an
ON
clause was not optimized as in MySQL 5.7,
so that, in later versions, the query executed more quickly
without the impossible condition than with it. An example of
such a query, impossible condition included, is SELECT
* FROM t1 JOIN t2 ON t1.c1=t2.c1 AND 1=2
.
(Bug #34668756)
When a user defined function was part of a derived table that was merged into the outer query block, or was part of a subquery converted to a semi-join, knowledge of whether this UDF was deterministic (or not) was lost during processing. (Bug #34666531)
With JSON logging enabled and an event subclass specified in the
audit log filter definition, an empty item ("" : {
}
) was appended to the end of the logged event.
(Bug #34659904)
Some subqueries did not execute properly. (Bug #34616553)
After the asymmetric_encrypt()
component function in a SELECT
query encountered a NULL field to decrypt, it could return NULL
values for other non-NULL encrypted fields.
(Bug #34598912)
The server did not always shut down cleanly after uninstalling the audit log plugin. (Bug #34594035)
Certain antijoins were not handled correctly by the server. (Bug #34370673)
References: This issue is a regression of: Bug #30573446.
When the MySQL 5.7 Optimizer has 2 choices for an index to
filter rows, one primary and one secondary, it picks a range
scan on the secondary index because the range scan uses more key
parts. MySQL 8.0 did not use this logic, instead choosing the
primary index to filter rows with WHERE
clause filtering. Primary key use is not suitable in such cases
due to the presence of LIMIT
, and due to the
nature of data distribution. The secondary index was not
considered while resolving order by due to constant elimination.
This resulted in much different query plans in MySQL 5.7 and
MySQL 8.0 for the same query.
We solve this issue in MySQL 8.0 by skipping the constant key
parts of the index during order-by evaluation only if the query
is constant-optimized, which can be done at this time, but not
during LIMIT
analysis.
(Bug #34291261)
The MySQL data dictionary caches failed lookups of
se_private_id
values (IDs which are not
found), which speeds up execution of code specific to
InnoDB
, relying on the fact that
InnoDB
does not reuse these IDs. This
assumption does not necessarily hold for other storage engines,
most notably NDB
, where this
problem was resolved previously by not using this cache.
We extend the previous fix made for NDB
so
that the cache lookup is now employed only when the table uses
the InnoDB
storage engine.
(Bug #34145006)
References: See also: Bug #33824058.
Unexpected results were seen in some queries using
DENSE_RANK()
, possibly with the
addition of WITH ROLLUP
.
(Bug #34099408)
Fixed an assert raised in
sql/sql_tmp_table.cc
following work done
previously to reimplement ROLLUP
processing.
(Bug #33830659)
References: This issue is a regression of: Bug #30969045.
Some CTEs that did not use any tables were not always handled correctly. (Bug #33725542)
References: This issue is a regression of: Bug #27062031.
Accessing rows from a window frame of a window function call
present only in the query's ORDER BY
list raised an error.
(Bug #33069747)
PERCENT_RANK()
used with
ORDER BY
did not return the correct result.
(Bug #33064174)column
References: This issue is a regression of: Bug #27484133.
The --exclude-tables
and
--include-tables
mysqlpump options did not handle views.
(Bug #21303549)
Changed the MySQL systemd service unit configuration from
After=network-online.target
to
Wants=network-online.target
to ensure that
all configured network devices are available and have an IP
address assigned before the service is started.
(Bug #109996, Bug #35068274)
AVG(...)
OVER (ROWS
BETWEEN 1 FOLLOWING AND UNBOUNDED FOLLOWING)
did not
return the correct result.
(Bug #109725, Bug #35013880)
References: This issue is a regression of: Bug #108008, Bug #34431996.
A query of the form SELECT 1 FROM t1 WHERE NOT EXISTS
(VALUES ROW(1), ROW(2))
caused an assert in debug
builds when the subquery_to_derived
optimizer
switch was enabled.
(Bug #109723, Bug #35014318)
References: See also: Bug #108910, Bug #34746261.
mysqlimport did not escape reserved word
table names when used with the
--delete
option.
(Bug #109711, Bug #34999015)
When cloning a condition to push down to a derived table,
characters in strings representing conditions were converted to
utfmb4
correctly only for values less than
128 (the ASCII subset), and code points outside the ASCII subset
were converted to invalid characters, causing the resulting
character strings to become invalid. For derived tables without
UNION
, this led to problems when
a column name from the derived table used characters outside the
ASCII subset, and was used in the WHERE
condition. For derived tables with UNION
, it
created problems when a character outside the ASCII subset was
present in a WHERE
condition.
We fix these issues by initializing the string used for representing the condition in such cases to the connection character set. (Bug #109699, Bug #34996488)
Using --single-transaction
with mysqldump version 8.0.32 required either
the RELOAD
or
FLUSH_TABLES
privilege. This
requirement now applies only when both
gtid_mode=ON
(default
OFF
) and with
--set-gtid-purged = ON|AUTO
(default AUTO
).
(Bug #109685, Bug #109701, Bug #34993824, Bug #34998910, Bug #35020512)
References: This issue is a regression of: Bug #105761, Bug #33630199.
Fixed a number of issues present in the internal documentation
for the scramble generator algorithm in
sha256_scramble_generator.cc
and
sha2_password_common.cc
.
Our thanks to Niklas Keller for the contribution. (Bug #109576, Bug #34967141)
CREATE USER IF NOT
EXISTS
added a password history entry even when the
user already existed and the password was not updated. This
caused a subsequent ALTER USER
statement to be rejected.
(Bug #109415, Bug #34906592)
Many joins using eq_ref
access did not
perform as well as in previous versions. This issue was first
reported in MySQL 8.0.29.
(Bug #109361, Bug #34891365)
A hash outer join sometimes incorrectly matched
NULL
with a decimal zero or an empty string
that used a non-padding collation, leading to erroneous results.
(Bug #109211, Bug #34837464)
References: This issue is a regression of: Bug #33794977.
An object used internally by ALTER INSTANCE
RELOAD TLS
was not freed until the number of readers
reached 0, under the assumption is that the number of readers
should reach 0 fairly frequently. The read lock held during an
SSL handshake is generally an expensive operation, with network
calls, so when roundtrips between the client and the server took
excessively long, the lock was held for a relatively long amount
of time. This meant that, when changing the value of this object
and there were a sufficient number of incoming SSL connections
being made, the number of readers might not reach 0 in a
reasonable length of time, leaving the thread holding the lock
using 100% of the CPU until the lock was released.
We fix this by adding a wait after setting the pointer to this object to a new value, but before releasing the old object.
Our thanks to Sinisa Milivojevic for the contribution. (Bug #107567, Bug #34284186)
If mysqldump or mysqlpump
could not convert a field's default value to UTF-8 (for
instance, if the field was of type
BINARY
and the default value did
not coincide with valid UTF-8), the operation produced results
that were not valid to import. Further, using the
--hex-blob
option did not resolve the issue. We
now convert the default value to the system character set. If
this fails, the server sends the value as hexadecimal instead to
make it more human-readable.
(Bug #104840, Bug #33322551)
A connection using the C API (libmysqlclient
)
client library could fail with the FUTURE
crypto policy.
(Bug #104778, Bug #33316709)
While cloning a temporary table for a common table expression which used shared materialization, the cloned temp table was not marked as using hash deduplication, leading to wrong results. We now set the hash field for the cloned temporary table correctly, and update the hidden field count to take this into account. (Bug #102251, Bug #32383712)
References: See also: Bug #103052, Bug #32659629.
CREATE EVENT
and
ALTER EVENT
assumed that all
values passed to them (other than in a DO
clause) resolved as scalars without actually checking the
values. This led to assertions when any such values actually
rows.
We now perform an explicit check for the number of columns when resolving such items, and report an error when one produces a row and not a scalar value. (Bug #57552, Bug #11764690)
A view reference whose underlying field is a constant is not marked as constant when the reference is part of an inner table of an outer join. It was found that, when pushing a condition down to a derived table, the reference was stripped off and only the underlying field was cloned, which made it a constant, and led to wrong results.
To fix this problem, we ensure that we do not push such a condition down to the derived table by adding a check to see first whether the table used by the condition matches the derived table or is a constant expression; only when it is one or the other of these do we actually push the condition down. (Bug #34661, Bug #11747971)